# What is Grok 4.5? xAI's new model, explained > Grok 4.5 is xAI's new model, now in private beta at SpaceX and Tesla with no public benchmarks. *Elon Musk just put a giant new Grok in beta at SpaceX and Tesla. Here's what's real, what's just a claim, and why you can't try it yet.* By The SuggestedTech Team · SuggestedTech Canonical: https://suggestedtech.com/news/what-is-grok-4-5-explained If you've seen headlines saying Elon Musk's new Grok 4.5 might beat one of the best AI models around, here's the calmer version. Yes, xAI has a new model. No, you can't use it. And the 'might beat Claude' part is Musk's claim, not something anyone outside his companies has actually checked. ## What actually happened On 28 June 2026, Musk posted on X that Grok 4.5 had entered a private beta at two of his companies, SpaceX and Tesla. 'Private beta' means a small, invite-only test — in this case limited to engineers at those firms. It's the first time Grok 4.5 has been used anywhere that we know of, and it comes before any public launch. > Grok 4.5 has entered private beta at SpaceX and Tesla, running on xAI's ninth-generation V9 foundation architecture at roughly 1.5 trillion parameters, ahead of any public release. > — [Crypto Briefing](https://cryptobriefing.com/grok-4-5-private-beta-spacex-tesla/), 2026-06-28 > **Info:** In plain English: Grok 4.5 is like a car being test-driven only by the manufacturer's own staff. It exists, it's running, but the public showroom isn't open — and no outside reviewer has driven it. ## How big is it, and what's it good at? Grok 4.5 runs on xAI's ninth-generation design, called **V9**, which finished its main training on 26 May 2026 with 1.5 trillion parameters. Parameters are roughly the number of internal dials a model can tune; more can mean more capacity, though not automatically better answers. That's about three times the size of the smaller Grok that currently replies on X and in Tesla cars. xAI also reportedly trained it on data from **Cursor**, a popular AI coding tool, which hints Grok 4.5 is aimed at writing and reasoning about code. ## The big catch: no proof yet Here's the part worth remembering. Musk said early tests put Grok 4.5 close to, or above, Anthropic's Claude Opus — a top model. But xAI hasn't released any benchmark scores or a 'system card' (the document labs publish explaining how a model was tested and where it struggles). The only people who've tried it work for SpaceX and Tesla, which Musk controls. And none of the independent scoreboards the industry trusts — like LMArena or SWE-bench — has tested it. So treat 'beats Claude Opus' as a claim to check later, not a fact. > Musk said Grok 4.5 had entered private beta at SpaceX and Tesla, with xAI planning to release a new foundation model each month through the end of 2026. > — [Let's Data Science](https://letsdatascience.com/news/musk-says-grok-45-enters-private-beta-at-spacex-tesla-1840769e), 2026-06-28 One more thing to expect: xAI says it plans to put out a brand-new model roughly every month for the rest of 2026, with these V9 versions (4.5, 4.6, 4.7 and so on) building towards a bigger model called Grok 5. So if you're waiting to actually try Grok 4.5, the more useful question may be which version reaches the public first — and whether it arrives with real numbers attached. Let's put the 'is it actually good?' question in perspective, because it's the one that matters to you. Benchmarks exist precisely so buyers don't have to take a company's word for it — they're the independent report card. When a lab skips them, it's asking you to trust the marketing instead of the marks, and the sensible response is patience, not excitement. That's not cynicism about Grok specifically; it's the same standard you'd apply to any product that says 'trust us, it's the best' without showing the test results. The good news is that this usually resolves itself quickly. Once a model reaches the public or an outside evaluator, independent scores tend to appear within days, and the picture gets a lot clearer. So the practical advice is simple: if you're curious about Grok 4.5, bookmark it and check back when it's actually available and someone neutral has tested it. If it's as good as Musk says, the numbers will show it and you'll have lost nothing by waiting. And if the numbers never show up at all, that itself is your answer — genuinely great models tend to want to be measured. ## Key takeaways - Grok 4.5 is xAI's newest AI model, announced by Elon Musk on 28 June 2026. - It's in a private beta at SpaceX and Tesla, so only their engineers can use it — there's no public access yet. - It runs on xAI's V9 design with 1.5 trillion parameters, about three times the smaller Grok on X today, and is tuned for coding. - Musk says it's close to Anthropic's Claude Opus, but that's his claim — xAI has shown no benchmarks or system card. - No independent scoreboard like LMArena or SWE-bench has tested Grok 4.5 yet. ## FAQ ### Can I use Grok 4.5 right now? No. It's in a private, invite-only beta limited to SpaceX and Tesla engineers as of 28 June 2026. It isn't on Grok's app on X, isn't on the public API, and isn't open to outside developers. ### Is Grok 4.5 really better than Claude Opus? We don't know. Musk said early tests put it close to or above Anthropic's Claude Opus, but xAI hasn't shown any benchmark scores or a system card, and only its own engineers have tried it. It's a claim, not a proven result. ### What does 1.5 trillion parameters mean? Parameters are roughly the internal dials a model can adjust as it learns. 1.5 trillion is a very large count — about three times the smaller Grok on X — which can mean more capacity, but a bigger number doesn't guarantee better answers. ### What is a system card, and why does it matter that Grok 4.5 doesn't have one? A system card is a document labs publish explaining how a model was tested and where it fails. Without one, there's no public record of Grok 4.5's safety testing or weaknesses, so its frontier-level claims can't be checked. ### When will Grok 4.5 or Grok 5 be public? xAI hasn't given a firm public date. It says it plans to release a new model each month through end-2026, with V9 versions building towards a larger Grok 5, so a public release could come via one of those upcoming versions. ## Sources - [Grok 4.5 Enters Private Beta at SpaceX and Tesla: No Public Access, No Independent Benchmark](https://www.techtimes.com/articles/319314/20260629/grok-45-enters-private-beta-spacex-tesla-no-public-access-no-independent-benchmark.htm) — Tech Times, 2026-06-29 - [Grok 4.5 enters private beta at SpaceX and Tesla with 1.5 trillion parameters](https://cryptobriefing.com/grok-4-5-private-beta-spacex-tesla/) — Crypto Briefing, 2026-06-28 - [Musk Says Grok 4.5 Enters Private Beta at SpaceX, Tesla](https://letsdatascience.com/news/musk-says-grok-45-enters-private-beta-at-spacex-tesla-1840769e) — Let's Data Science, 2026-06-28